This came in via the trac account request. I don't know the sender's email address ...
-- h ---------- Forwarded message ---------- From: 'Jamel Dammak' via sage-trac-account <[email protected]> Date: Sun, Dec 11, 2016 at 10:01 PM Subject: [sage-trac-account] Corrections about the function "is_prime" for graphs To: "[email protected]" <[email protected]> Dear sir, there is an error concerning the function "is_prime" for graphs in Sagemath, section Graph Theory. Here is a conter-example. g1=Graph({0:[1,4],1:[0,2,4],2:[1,3,4],3:[2],4:[0,1,2]});g2=Graph({0:[1],1:[0,2,4],2:[1,3,4],3:[2,4],4:[1,2,3]}) #g1.show();g2.show(); #[1,4] is a module of g1 so g1 is not prime g2.is_isomorphic(g1), g1.is_prime(),g2.is_prime() This is a conter-example with two isomorphic graphs g1 and g2 on 5 vertices giving two different results with the function "is prime". I have an algorithm giving the list of all prime graphs on at most 8 vertices. Best regards. -- -- You received this message because you are subscribed to the Google Groups "sage-trac-account" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-trac-account --- You received this message because you are subscribed to the Google Groups "sage-trac-account" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
